Field
The present invention relates generally to surgical staples used for compressing bones or bone fragments. More specifically, the invention relates to surgical staples including a first leg for anchoring in a first bone or bone fragment, a second leg for anchoring in a second bone or bone fragment, and a bridge connecting the first leg and the second leg. The invention also relates to an instrument for holding and implanting surgical staples.
Description of Related Art
Surgical staples are used to treat angular deformations, fractures particularly with respect to the extremities, subluxation, dislocation, arthritis, or other issues that may occur with regard to bones of the human body. The staples are attached to respective bones or bone fragments to fuse the bones or bone fragments together while exerting a compressive force on them. Staples are advantageous over other fusion techniques such as plates, for example, in view of their compactness and flexibility.
Document U.S. Pat. No. 6,908,467 B2 discloses a distraction device made from a nitinol wire which includes an S-curve and bent end regions provided with hooks for anchoring in the bony material. When the distraction device is implanted, a rise of the temperature above the transfer temperature causes the shape memory material to change from a martensite state to an austenite state. The device is distracted when the S-curve assumes an elongated shape in the austenite state. The hooks self-lock in the opposing bone surfaces and the bone sections distract. Due to the superelastic characteristics of Nitinol, the distraction force remains more constant.
Document U.S. Pat. No. 7,618,441 B2 discloses a bone staple which may be made of Nitinol. The staple has a bridge and legs extending from corner joints adjacent respective end portions of the bridge. The bridge may be slightly arc-shaped whereas the legs extend parallel to each other. The bridge also slightly extends beyond the corner joints thereby forming stop means or shoulders. The shoulders serve for reinforcing the connection between the legs and the bridge, and, since the level of the shoulder is lower than the bridge, for preventing the bridges from entering into contact with the bone. The staple is used to address convexity or concaveness of the vertebral column, wherein the shape memory effect of Nitinol is employed to splay the legs of the staple inserted into respective vertebrae away from each other.
Document GB 2471648 B discloses a staple for bones. The staple may be made of a shape memory material such as NiTi and has a connector including a ring of curved portions allowed to be distracted and further including three or four legs arranged parallel to each other.
Document US 2013/0026206 A1 discloses a bone staple which has a bridge connecting two legs and which is made from Nitinol. The bridge has an S-shape in a plane perpendicular to that of the legs and the legs are inclined toward each other in a closed configuration. In an opened configuration, the legs become parallel.
Document US 2013/0231667 A1 discloses a surgical staple having a middle section or bridge and side sections or legs which cantilever from ends of the middle section at an angle close to 90°. In a relaxed configuration, the middle section is curved within the plane of the side sections and has an angle of curvature between 15° and 35°. The side sections extend towards each other in this configuration. Use of Nitinol superelastic material is also disclosed therein.
Document US 2014/0277516 A1 discloses a bone staple including a bridge and legs extending from ends of the bridge. The bridge has a straight shape in a relaxed as well as in a splayed configuration of the legs. To splay the legs, the staple is put on a storage block and two tips of respective pivoting inserter handles force the side legs into the splayed configuration at 90° relative to the bridge. The staple is made from a super elastic and shape memory material such as Nitinol ASTM 2063.
Document US 2014/0358187 A1 discloses a surgical staple and a staple insertion device. The staple may be made of Nitinol and has a bridge and legs extending from ends of the bridge. To achieve a tensioned configuration in which the legs are parallel to each other, the staple is loaded to jaws of the insertion device which may be rotated outwards by means of a spacer configured to separate the jaws, which adversely engage the legs of the staple.